Fire extinguishing compound



Patented Aug. 20,1940

UNITED STATES PATENT orriss 2,212,470 .rmn EXTINGUISHING COMPOUND KarlFriedrich, Berlin-Wllmersdorf, Germany No Drawing. Applllilcation Juneis, 1939, Serial Germany May 4, 1938 Claims. (CI. 23-11) resistance toheat and other physical or chem ical influences than the foams hithertoknown.

Consequently the extinguishing compoundform-' ing the object of theinvention is especially suitable for cases injwhich an otherwise hardlyextinguishable fire, as for instance that caused by alcohol, aromatichydrocarbons and the like, is to be combated.

The compoundaccording to the invention consists in a mixture ofsolubilized proteins or materials containing protein and a smallpercentage ofa soluble aluminum compound. The inventor hasascertainedthat even a very small addition of a soluble aluminumcompound sufiices to increase the stability or a foam produced by meansof proteinous material to a considerable extent. Suchaluminum compoundsmay be, for instance. as aluminum salts or aluminates. The fire extingcompound according to the invention may be obtained, for instance, inthe following manner: 7

1 kilogram of keratin is solubilized by. heating m the material with 150grams of slaked lime and 3 to 5 kilograms of water. The resulting massis neutralized by the addition of surfuric acid and subjected tofiltration. The filtrate is-evaporated to a specific gravity-o! 1.15. To1 kilogram of 5 the resulting liquid a solution of 20 grams of aluminumhydroxide in an excess of acetic acid is added whilst stirring andfinally the liquid is neutralized solution.

by v the addition oi. caustic soda A solution of -1 kilogram of this.liquid in 20 liters of water when subjected to the action of a suitableair-foam producer is transformed into an extraordinarily tough foam fromwhich the liquid contained therein separates twice to three 6 times asslowly as a foam obtained under similar conditions from a solutionhaving the same strength without the addition of an aluminum compound.

Instead of aluminum acetate another soluble 10 aluminum compound, forinstance, aluminum lactate or an aluminate may be added to the foamforming liquid. The use of aluminum salts of organic acids has provedespecially advantageous. I5-

I claim:

1. A foam-forming compound for extinguishing fire, consisting of asolution of a solubilized proteinous material and a small quantity of asoluble aluminum compound. 20

2. A foam-forming compound for extinguishing fire, consisting of asolution or a solubilized keratinous material and a small quantity of asoluble aluminum compound.

3. A foam-forming compound for extinguishing fire, consisting of asolution of a solubilized pro- "teinous material and a small quantity ofa soluble aluminum salt 01' an organic acid.

4.A-foam-1orming compound for extin ishing fire. consisting of asolution of a solubilized proteinous material and a smallquantity ofaluminum acetate.

5. A foam-forming compound for extinguishing fire, consisting or asolution of a solubilized proteinous material and a small quantity ofalumi- 1mm lactate.

; KARL FRIEDRICH.

